An Adaptive and Fault-Tolerant Routing Algorithm for Meshes

Abstract

We propose a partially adaptive fault-tolerant and deadlock-free routing algorithm in n-dimensional meshes based on the fault-tolerant planar-adaptive routing and Duato's protocol. In particular, we show that only four virtual channels per physical channel are sufficient for tolerating multiple faulty regions even in the case of n-dimensional meshes. Our scheme is able to handle faulty blocks whose associated fault rings have overlaps. In addition, it can be used to route messages when fault regions touch the boundaries of the mesh. A flag bit is introduced for guiding misrouted messages. Messages are routed adaptively in healthy regions of the network. Once a message faces a faulty region, it is routed around it using a non-minimal path. A flit-level simulator is employed to evaluate the performance of the proposed algorithm and to compare its performance to those already introduced.